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        검색결과 501

        363.
        1999.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present BVRI CCD photometry and near-infrared K photometry of the intermediate-aged open cluster NGC 7790. The reddening, E(B - V) = 0.54 ± 0.05 and the distance modulus, (m - M)o = 12.45 ± 0.10 for the cluster were determined by zero-age-main-sequence fitting and theoretical isochrone fitting using not only (V, B - V), (V, V - 1), (V, V - R) but also (V, V - K) color-magnitude diagrams. The reddening corresponded approximately to the average value derived from previous studies, while the distance modulus was found to be almost midway between the CCD photometric results of Romeo et al. (1989) and those of Mateo & Madore (1988). We have used four colors to distinguish members from field stars. The expected colors were calculated using the derived distance modulus, and were then were compared with the observed colors (B - V), (V - 1), (V - R), and (V - K). Thus, a color excess E(B - V) for each star was determined which could give the minimum difference between the calculated and observed colors. Single and binary members of the cluster were determined on the basis of the E(B - V) distribution of stars.
        5,100원
        364.
        1999.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Diffuse radio emission in Abell 2256 was detected above 3 σ with DRAO observations at 1420 MHz. The halo size is ~13'×10' (~1h 50 -1) in full extent and is elongated along a position angle of about 112°. The total flux density contained in the halo is 30±10 mJy at 1420 MHz and its spectral index is -2.04±0.04, showing no evidence for steepening up to 1420 MHz. Using the size estimate, yields a more reliable equipartition magnetic field strength which is 0.34(1 + k)2/7 μG. In addition, five new radio sources are identified.
        4,000원
        365.
        1999.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present a new UBVI CCD photometry of the intermediate-age open cluster NGC 2420. Our photometry covers a field of 7′9×7.′7 7′9×7.′7 of the sky centered on the cluster. We determined the reddening and distance to the cluster by the main sequence fitting as E(B−V)=0.05±0.02 E(B−V)=0.05±0.02 and (m−M)o=11.9±0.1 (m−M)o=11.9±0.1 , along with the age of \~2 \~2 Gyr by fitting the Padova isochrones to the observed color-magnitude diagrams of the cluster. The fraction of binaries is found to be 44±5% 44±5% and they are likely to locate in the central region of the cluster. The spatial distributions of the binaries and the variation of the cluster luminosity functions along the radius suggest mass segregations due to the dynamical evolution of the cluster.
        4,000원
        373.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        육묘시 주간/야간 온도 처리가 서광 토마토 묘의 정식후 초기결실 절위 및 생육에 미치는 영향을 알아보고자 실험을 수행하였다. 2차에 걸쳐 환경조절실 내에서 육묘하여 유리온실 내에서 양액재배 하였다. 서광 토마토 종자를 상토를 채운 128구 플러그 트레이에 파종하여 생육상에서 3일간 발아시킨 후 주간/야간 온도가 25℃/25℃, 16℃/16℃, 16℃/25℃ 또는 25℃/16℃로 각각 조절되는 4개의 생육실에서 1차 실험은 33일, 2차 실험은 35일간 육묘하였다. 일일 12시간씩 3파장 cool-white 형광램프로 140μmol.m-2 .s-1의 광을 공급하고, 2차 실험에서는 1000μmol.mol-1의 CO2를 공급하였으며, 공기 유속은 0.3m.s-1, 그리고 공기 중 습도는 80%를 유지하였다. 육묘한 토마토 묘를 자연 일장조건인 유리온실의 암면 슬레브에 이식하여 1차 실험은 37일간, 그리고 2차 실험은 35일간 재배하면서 육묘시에 사용했던 양액과 동일한 양액을 공급하였다. 초장은 주간과 야간 온도의 상호작용보다는 일평균 온도의 영향을 더 많이 받았으며, 16/16℃ 처리구에서 가장 컸다. 엽구는 주간과 야간의 기온의 영향을 받지 않았고, 엽록소 농도는 16/25℃ 처리구에서 가장 높았다. 그리고 줄기의 생체중과 건물중은 주야 항온 처리구에서 타처리에 비해 다소 큰 경향이었다. 제 1화방과 2화방의 절위는 25/25℃구에서 1화방의 착생 절위가 유의성 있게 높았고, 나머지 처리들간에는 차이가 없었다. 1화방 1번화의 개화 소요일수는 25/25℃구에서 가장 컸고 16/25℃구에서 낮았다. 토마토의 생육과 1, 2화방 절위에 육묘시의 일평균 기온이 큰 영향을 미치는 것으로 나타났으나 토마토의 2화방 비절현상은 나타나지 않았다.
        4,000원
        377.
        1998.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The VI CCD photometry is made for stars in the globular cluster M22 down to V ≈ 19m, I ≈ 18m. In the color-magnitude diagram (CMD), red giant branch (RGB), asymtotic giant branch (AGB) and blue horizontal branch (BHB) are well defined. The luminosity functions (LF) of RGB, AGB and BHB stars are derived, discussing deficient gaps and bumps in the CMD. The anomalously wide RGB seen in the BV photometric system is found to disappear in the VI photometric system.
        4,000원
        378.
        1998.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present UBV CCD photometry of Be 2, previously unstudied open cluster. Our photometry covers a field of 3'.2×3'.8 of the sky centered on the cluster, which is slightly smaller than the cluster diameter estimated to be about 260". We have determined the reddening, distance, age and metallicity of the cluster by fitting the Pad ova isochrones to the observed stellar distributions in color-magnitude diagram as well as main sequence fitting: E(B-V)=0.8±0.05, (m-M)o=13.6±0.1, log(t) =8.9±0.1, and Z=0.008. The present photometry shows that Be 2 is a distant open cluster of intermediate age. that it is a distant intermediate-age open duster.
        4,300원
        379.
        1998.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The wide field (~20'×20') CCD photometry has been performed for more than 4,000 stars over a whole region of NGC 362 which is located inside the SMC halo. The Color-Magnitude diagram (CMD) and luminosit function (LF) for red giant branch (RGB) stars are presented, discussing a distinct bump along the RGB and some blue stars appearing in the blue horizontal branch (BHB) and above BHB. The anomalous globular cluster NGC 362 with highly populated red horizontal branch (RHB) stars is compared with the another anomalous globular cluster NGC 288 with highly populated BHB stars. A metal-rich, young blue component and metal-'poor, old red component of the SMC halo stars are examined.
        4,000원
        380.
        1997.12 구독 인증기관·개인회원 무료